The document explains how computers function in relation to programming, emphasizing the roles of hardware components like the CPU and memory, alongside software elements such as programming languages. It outlines the fetch-decode-execute cycle and differentiates between compilers and interpreters, with an overview of operating systems and input/output operations. Additionally, it discusses the importance of efficient code and the difference in perception between programmers and computers.

1. How Computer Works in the
Context of Programming

2. Hardware and Software
• • Hardware: Includes CPU, memory,
input/output devices.
• • Software: Instructions written in
programming languages.

3. The CPU: The Brain of the
Computer
• • Central Processing Unit (CPU) executes
instructions.
• • Consists of Control Unit (CU) and Arithmetic
Logic Unit (ALU).

4. Fetch-Decode-Execute Cycle
(Instruction Cycle)
• 1. Fetch: Retrieve instruction from memory.
• 2. Decode: Interpret the instruction.
• 3. Execute: Perform the instruction.
• 4. Store: Write back result to memory.

5. Memory and Storage
• • RAM: Temporary storage for running
programs.
• • Storage (Hard Drives/SSDs): Permanent data
storage.

6. Programming Languages
• • High-Level Languages: Python, Java, C++ are
easier for humans to understand.
• • Low-Level Languages: Assembly is closer to
machine code.

7. Compilers and Interpreters
• • Compiler: Converts high-level code to
machine code before execution (e.g., C, C++).
• • Interpreter: Executes code line-by-line (e.g.,
Python).

8. Operating System (OS)
• • OS manages hardware, memory, and
processes.
• • Acts as an intermediary between software
and hardware.

9. Input/Output (I/O) Operations
• • Programs interact with external devices for
input/output.
• • Programming languages provide APIs for
handling these operations.

10. How Code Runs: A Simple Example
• 1. Write the code (e.g., C program).
• 2. Compile into machine code.
• 3. OS loads program into memory and CPU
executes instructions.

11. Efficiency and Performance
• • Efficient code uses memory, CPU, and I/O
operations effectively.
• • Optimization helps improve performance.

12. Programmer’s vs Computer’s
Perception
• • Programmer sees the program as a set of
commands (syntax).
• • Computer processes them as binary
sequences.